A353491 a(1) = 1, and for n > 1, a(n) = 1 if the largest proper divisor of n is of the form 4k+1, otherwise 0.

1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Formula

a(n) = 1 iff A353490(n) = 1, otherwise 0.

Prog

(PARI)
A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));
A353491(n) = (1==(A032742(n)%4));

Crossrefs

Cf. A032742, A353490, A353492.

Sequence in context: A100923 A050073 A266843 * A120474 A266789 A098370

Adjacent sequences: A353488 A353489 A353490 * A353492 A353493 A353494

Keyword

nonn

Author

Antti Karttunen, Apr 22 2022

Status

approved